1. Field of the Invention
The present invention relates to an optically active monoester compound of the formula (I) or (I'), ##STR2## where R is an alkyl group of 1 to 15 carbon atoms and a process for producing said compound.
2. Description of Related Art
Syntheses of intermediates for pharmaceuticals and biologically active substances have recently increased. As a result, optically active starting materials for the syntheses of those materials are now in demand.
In particular, optically active analogues of bicyclo [2,2,2] oct-5-ene appear to be useful as starting materials for producing biologically active substances, but there are not so many compounds capable of being actually used therefor.
A compound of the formula, ##STR3## is known as a very useful compound as a starting material for biologically active substances such as a starting material for prostaglandin.
However, known processes for producing said compound are not practical. For example, J. B. Jones etal.: J. Am. Chem. Soc., Vol. 107, pp. 2521-6 (1985) discloses that the optically active lactone compound (III) above can be produced by converting a diol of the formula, ##STR4## using a horse liver dehydrogenase.
However, this process has various drawbacks, e.g. the catalyst, horse liver dehydrogenase is expensive and, in addition, not easily available; a large amount of NAD (nicotinamide-adenine dinucleotide) is required; the reaction time is long (minimum 6 days) and the post-treatment is complicated (ether extraction for 12 hours).
In view of the foregoing, optically active analogues of bicyclo [2,2,2] oct-5-ene are in demand, but practically usable compounds have not yet been found. The present inventors did research and investigated these problems. They have now completed the present invention.